全文获取类型
收费全文 | 850篇 |
免费 | 100篇 |
专业分类
950篇 |
出版年
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 18篇 |
2015年 | 27篇 |
2014年 | 35篇 |
2013年 | 36篇 |
2012年 | 54篇 |
2011年 | 41篇 |
2010年 | 30篇 |
2009年 | 30篇 |
2008年 | 38篇 |
2007年 | 33篇 |
2006年 | 30篇 |
2005年 | 42篇 |
2004年 | 24篇 |
2003年 | 39篇 |
2002年 | 30篇 |
2001年 | 33篇 |
2000年 | 27篇 |
1999年 | 28篇 |
1998年 | 17篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 17篇 |
1994年 | 5篇 |
1993年 | 12篇 |
1992年 | 26篇 |
1991年 | 19篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 9篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1969年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有950条查询结果,搜索用时 15 毫秒
101.
In the course of performing approximately 100 orbital aspirates, glandular epithelial inclusions were seen in three specimens from three patients. These inclusions, now recognized as benign and normal structures, initially led to false-positive cytologic results in two of the three cases. On the basis of reconstructing the clinical events, they appear to have been derived from the minor lacrimal glands in two cases and from the major lacrimal glands in the third. The potential hazard of regarding these glandular inclusions as indicating metastatic neoplasm is emphasized. 相似文献
102.
103.
104.
We report a structural characterization by electron microscopy and image analysis of a supramolecular complex consisting of seven trimeric light-harvesting complex II proteins. The complex was readily observed in partially-solubilized Tris-washed photosystem II membranes from spinach but was also found to occur, with a low frequency, in oxygen-evolving photosystem II membranes. The structure reveals six peripheral trimers with the same rotational orientation and a central trimer with the opposite orientation. We conclude that the heptamer represents a naturally occurring aggregation state of part of the light-harvesting complex II trimers in the thylakoid membranes. 相似文献
105.
106.
Deinococcus radiophilus strain ATCC 27603 contains, apart from endonuclease DraI [1], two additional sequence-specific endonucleases. These enzymes, designated DraII and DraIII, recognize nucleotide sequences with novel specificities, PuG↓GNCCPy and CACNN↓GTG, respectively. 相似文献
107.
108.
109.
Assessment of the cellular localisation of the annexin A2/S100A10 complex in human placenta 总被引:1,自引:0,他引:1
The AnxA2/S100A10 complex has been implicated in various placental functions but although the localisation of these proteins individually has been studied, there is no information about the localisation of their complex in situ at the cellular level. Using the proximity ligation technique, we have investigated the in situ localisation of AnxA2/S100A10 complex in the placenta and have compared this with the location patterns of the individual proteins. High levels of expression of AnxA2/S100A10 complexes were observed in the amniotic membrane and in blood vessel endothelial cells. Lower levels were detected in the brush border area of the syncytium and in the trophoblasts. Immunohistochemical analysis of AnxA2 and S100A10 individually revealed broadly similar patterns of localisation. The brush border staining pattern suggests that in this location at least some of the AnxA2 is not in complex with S100A10. The formal location of the AnxA2/S100A10 complex is compatible with a role in cell–cell interaction, intracellular transport and secretory processes and regulation of cell surface proteases, implying contributions to membrane integrity, nutrient exchange, placentation and vascular remodelling in different parts of the placenta. Future applications will allow specific assessment of the association of the complex with pathophysiological disorders. 相似文献
110.
Ciro H. Sumida Ana Paula C. S. Araujod Douglas C. Peitl Lucas M. Abreu Robert F. H. Dekker 《Biocontrol Science and Technology》2018,28(2):142-156
Sclerotinia sclerotiorum is an important plant pathogen with worldwide distribution that causes severe economic losses of various agricultural crops such as soybean. This fungus is normally controlled with synthetic chemical fungicides that pose risks to the environment, and can be harmful to human health, and they can also induce resistance in pests. The aim of this study was to investigate the potential of Trichoderma asperelloides as a biocontrol agent towards white mold disease on soybeans crops. The antagonism of two strains of T. asperelloides (T25 and T42) isolated from soil samples was determined in-vitro by dual-culture confrontation testing on nine S. sclerotiorum strains obtained from sclerotia collected on diseased soybean plants. The mycelial growth and inhibition of carpogenic and ascospore germination by T. asperelloides extracts, as well as the efficacy of these on white mold control in soybeans were evaluated. Both strains of T. asperelloides exhibited high potential of antagonism. Methanolic and ethyl acetate extracts of the two T. asperelloides strains showed excellent growth inhibition (60–100%) on all of the pathogens tested. The ethyl acetate extracts of both T. asperelloides strains exhibited the highest efficacy against carpogenic germination, decreasing by 20–30% the number of ascospores per apothecium. Strains of T. asperelloides tested were more efficient in controlling white mold than two commercial products made from Trichoderma harzianum. The new strains of T. asperelloides have potential for successful biological control of white mold disease of soybean crops in the field. 相似文献